Location
Tasman Highway – Apsley River Bridge Replacement
What We Did
Construction of new 3 span bridge, realignment of highway and demolition of existing bridge.
Client
Department of State Growth
Contract Value
$7.5 Million
Date
January 21 – July 22
Details
Description
The Tasmanian Government committed to replacing the Apsley River Bridge and realigning over 1400m of highway on either side of the new bridge to improve the alignment so that it is suitable for travel at 100km/h. It was critical for the project to not impact the Ramsar listed wetland downstream of the bridge.
The project involved the construction of:-
- Supply, installation and/or construction of driven piles, abutments, wingwalls, Pile caps, piers, crossheads, precast concrete beams, deck slabs, kerbs, steel post and rail traffic barrier and approach slabs and scour protection.
- Supply and installation of embankment scour protection using 1.2m diameter quarry rock
- Constructing 1.4km of new road to cater for a road realignment
- Excavation, embankment ands pavement construction
- All stormwater and subsurface drainage
- All bitumen sealing and asphalt placement
- All road safety barrier construction
- Installation of traffic facilities including signage and linemarking.
- Construction of the Lilia Villa lane intersection to allow safer truck egress onto the Tasman Highway
- Demolition of the existing Apsley River Bridge
Special features of project:
- Constructing a river crossing platform suitable to withstand 1 in 5-year floods and heavy crane loads. The crossing was constructed using 1m to 2m wide scour rock that was sourced from a nearby local quarry.
- Demolition of the existing Apsley River Bridge
- Training on local concrete supplier to produce high performance concrete
- Flooding of Apsley River. Throughout the lift of the project, DCS endured 6 major floodings events, which saw water levels just below the beams.
- Piling within the river was complex due to the variable geotechnical conditions encountered once pile driving commenced. Every pile depth changed considerably as the hard rock level changed due to the terrain and large amounts of rock boulders encountered. The process required driving circular hollow section steel piles down to rock. If a boulder was encountered, the a down hole hammer needed to be used to remove the obstruction so that piling could recommence. Once the depth was reached, testing was required to determine the piles capacity. Reinforcement cages were then lowered, and concrete poured using a tremie line to finish off the piles
- Scour Rock Dual Purpose: Access over the river to construct the bridge was a major obstacle for the project. Given the size of the bridge, large 70T piling rigs and 300T cranes were required to support the bridge construction. The DCS team developed the idea to construct a river crossing using the large dolerite scour rock which was required to line the embankment for the final design. DCS engaged a Geotechnical Engineer to assess the suitability of the scour rock as a heavily loaded platform for a river crossing.
- DCS also engaged an environmental consultant (Marine Solutions) to undertake an environmental risk assessment in protecting the local fauna within the river’s ecosystem during the works. DCS were advised to install high stress geofabric along the riverbed to assist in protecting the benthos of the river. The benefit of using the scour rock was that it was already required for the project. This meant that DCS did not have to purchase additional rock that would have to be disposed of at the end of the project. By re-organising the construction program, DCS could facilitate the temporary reuse of the scour rock.
Contract Details
Form of Contract: AS2124 (BOQ)
Award Value: $7.5M (exc. GST)
Start Date: 6th January 2021
Original Contract Period:30th June 2022
Actual Completion Date: 16th July 2022
Liquidated Damages: Nil
Contractor Resources
Simon Heazlewood (Project Director)
Muhammed Khan (Project Manager)
Brett Dwyer (Project Supervisor-Bridges)
Patrick Murphy (Project Supervisor-Roads)
Principal Subcontractors
Roadways (Bituminous Surfacing)
Statewide Linemarking (Linemarking)
BridgePro (Piles)
Reveg Tasmania (Landscaping)
Geotas (Safety Barrier)
East Coast Concreting (Concreting)
Principal Suppliers
Wallaroo (Quarry Product)
Hudson Civil Products (Stormwater Pipe/Structures)
Geotas (Geofabrics and subsoil drains)
VEC (Bridge Beams)